In some instances a greater degree of braking action is required by railway vehicles, such as in the use of snowplows which must be moved at high rates of speed and, therefore, require a higher degree of braking in retarding or stopping the equipment. If an Automatic Train Operating Device (A.T.O.) is in use, it may be coordinated with manual brake operation to provide a higher degree of braking for railway cars by using a change-over valve device in a double input control pressure system.